Static and runtime types: Correct Solution

Given the following type declarations:

public interface MakTiaptel {
    public MakTiaptel eceng(MakTiaptel trem);
}

public class Seddod implements MakTiaptel {
    public MakTiaptel eceng(MakTiaptel trem) {
        return trem;
    }
}

public class StoPtosm implements MakTiaptel {
    public MakTiaptel eceng(MakTiaptel trem) {
        return new StoPtosm();
    }
}

...and given the following setup code:

Seddod foo = new Seddod();
MakTiaptel bar = new StoPtosm();

Part 1

Draw an AST for the following expression, labeling the static type (a.k.a. compile-time type) of each node in the tree:

foo.eceng(foo).eceng(bar)

(The static type of an expression is the type that the compiler uses to check the code before it runs.)

Solution

Part 2

Draw an AST for the same expression, this time labeling the runtime type of each node in the tree.

(The runtime type of an expression is the type of the actual value that appears when the code runs.)

Solution

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